Trap behavior in AlGaN/GaN HEMTs by post-gate-annealing

• Published in: Proceedings. IEEE Lester Eastman Conference on High Performance Devices, 2004 pp. 145 - 150
• Main Authors: Hyeongnam Kim, Jaesun Lee, Wu Lu
• Format: Conference Proceeding
• Language: English
• Published: Singapore IEEE 2004; World Scientific Publishing
• Subjects: Aluminum gallium nitride; Annealing; Applied sciences; Current measurement; Electron traps; Electronics; Electronics packaging; Exact sciences and technology; Fabrication; Gallium nitride; HEMTs; MODFETs; Pulse measurements; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Transistors; Breakdown voltage; High electron mobility transistor; Annealing; Electric breakdown; Time constant
• ISBN: 9789812561961; 981256196X
• DOI: 10.1109/LECHPD.2004.1549686

Trapping effects are investigated to examine the post-gate annealing effects on AlGaN/GaN high-mobility electron transistors (HEMTs) using pulsed I-V and transient measurements. In the unannealed devices, shallow traps are identified, which have an activation of 38 meV at a drain bias of 7 V. The time constant of these traps is determined to be -0.5 /spl mu/s. Devices annealed at 400 /spl deg/C for 10 minutes have a significantly smaller number of traps. However, a small number of traps with a longer time constant of 9.2 /spl mu/s are created or activated during post-gate annealing. 20-minute annealing at 400 /spl deg/C leads to the increase of the number of traps with emission time constants of 21.6 /spl mu/s and 1.25 ms. The breakdown voltage improvement by post-gate annealing is attributed to the removal or significant reduction of the shallow level traps.